Electric eye

Electric eye is a somewhat dated term used to describe an opto-electronic means of sensing something, most commonly a photodetector of some type. An example is the door safety system used on garage door openers that use a light transmitter and receiver at the bottom of the door to prevent closing if there is any obstruction in the way that breaks the light beam.

In the frequently played "Proper Modulation" soundbite from the Howard Stern Radio Show, Stern's father, a sound engineer, describes "the electric eye" as "a green type of... tube."

Examples

Detector for railway vehicles that exceed the loading gauge.

Translation of "Electric eye"

Hebrew: עין אלקטרונית.